In recent years, information processing devices are used in various systems. Meanwhile, power consumption of an information processing device varies according to change in a requested processing load and a processing status such that an application has a peak time. As such, in order to realize stable operation, power control in an information processing device is important. In particular, an information processing device such as a server device required to operate full time needs to avoid server down due to power supply shortage.
As a technology to control power of an information processing device in accordance with the abovementioned situation, for example, a technology called a power peak assist function as shown in Patent Document 1 has been known. In order to realize the power peak assist function, first, a power supply device and a battery are provided as a power supply module. Then, in addition to power supply by the power supply device to the information processing device, power supply by the battery assists power consumption of the information processing device as the power peak assist function.
An example of the power peak assist function will be further described specifically. First, in order to realize the power peak assist function, in addition to the power supply module described above, a peak assist control device, which controls power supplied from the power supply device and the battery to the information processing device, is provided. The peak assist control device extracts the residual amount of energy in the battery from the power supply module and, on the basis of the information, notifies permissible power consumption value to the information processing device. Thus, the information processing device can operate within the range of the notified power consumption value, and power is supplied from the power supply device and the battery up to the power consumption value. Further, in a case where the residual amount of energy in the battery is short, the peak assist control device controls the information processing device to operate within the value range of power available only from the power supply device.    Patent Document 1: Japanese Unexamined Patent Application Publication No. 2003-150281
The peak assist function described above fixes the setting of a power supply device upper limit value, which is the upper limit value of power available solely from the power supply device. However, in a case where the power supply device upper limit value is set to a low value, power supply by the power supply device is not enough and power is often supplied from the battery to the information processing device. In this case, the residual energy in the battery is reduced significantly, causing problems that the information processing device goes down due to battery shortage and that performance lowers because of occurrence of power capping. On the other hand, in a case where the power supply device upper limit value is set to a high value, opportunities to power supply by the battery are reduced, so that advantages of the peak assist function are not taken. This causes a problem of useless facilities. In other words, in a system having the peak assist function, the abovementioned problems arise in a case where the power supply device upper limit value is improperly set.